1. Field of the Invention
The present invention relates to a device for carrying out trans-esophageal echocardiography and a cardioversion, particularly for the treatment of arrhythmia.
2. Description of the Related Art
There will now be referred specifically to the arrhythmia which is the most frequent, which is auricular fibrillation, without thereby limiting the invention to this particular pathology. Auricular fibrillation is nowadays the arrhythmia most often encountered in a population more and more stressed and this the more as the population ages.
The risks connected with auricular fibrillation are numerous, particularly the risk of thromboembolic accident which can lead to cerebral vascular accidents responsible for very high morbidity and mortality, as well as a decrease of the cardiac flow due to loss of the auricular systole and to the change in systolic function of the left ventricle.
Thus, to prevent thromboembolic complications, to improve the left ventricular function and to recover the auricular systole, there is generally used a cardioversion to re-establish the sinusal rhythm in the patient by electric shock.
However, cardioversion can lead to cerebral vascular accidents or to peripheral embolisms, by detachment of all or a portion of the pre-existing thrombus at the level of the left auricle under the action of electric shock.
In the absence of reliable methods for the detection of thrombi, it was recommended to subject each patient to a treatment with anticoagulant for three weeks before the cardioversion and for four weeks after the return to normal sinusal rhythm, to dissolve any possible thrombi already existing. However, this treatment could lead to hemorrhaging, particularly in older subjects, to say nothing of possible complications connected to prolonged hospitalization.
Nowadays, it is possible to detect the presence of auricular thrombi by using trans-esophageal echocardiography, to visualize correctly the left auricle. A probe known for trans-esophageal echocardiography comprises generally an ultrasonic detector at the distal end of an endoscope. This latter method requires only a short anticoagulant regime for its use. When the result of trans-esophageal echocardiography reveals the absence of thrombi, one can proceed immediately to cardioversion.
Numerous methods of cardioversion are now known.
A first method consists in re-establishing the sinusal rhythm by pharmacological treatment by an oral or intravenous route. However, this method is of long duration and now is not always effective.
Another method consists in producing electric shocks internally or endocavitally. However, such a method of cardioversion is an invasive action and very difficult to use.
Still another method consists in producing electric shocks by esophagal route with an endoscope provided at its distal end with several electrodes. Although this operation does not require general anaesthetic, but only simple sedation, it can give rise to complications when it follows a preliminary trans-esophageal echocardiography. Thus, in practice, the operator sometimes encounters difficulties in reintroducing a new probe in the mouth of the patient through which it must pass, because there is a risk of rejection of the probe by the patent because the esophagal tissues are already irritated, to say nothing of the risks of injury or perforation of the esophagus by repeated introduction of endoscopes.
As a result, the cardioversion that is the most frequently used and preferred by doctors is cardioversion by external route in which two electrodes are simply applied to the thorax of the patient thereby to apply electrical discharges of the order of 300 to 360 J. This method is quite simple and easy to use for the doctor but it requires general anaesthetic for the patient.